| dc.description.abstract | In this study, we conducted field surveys of debris flows at the Houyenshan of San Yi county, Miaoli, Taiwan, and conducted particle experiments analysis of runoff-induced debris flows in the large-scale mechanics laboratory of National Central University. The former recorded the flow progress of the debris flow events through image data filmed by cameras, and found that the average velocities at the front of the debris flows were between 0.4 m/s-1.1 m/s. We collected the rainfall data of the debris flows occurred from 2016 to 2021, and concluded that the effective accumulated rainfall (including antecedent rainfall) (R) and the accumulated rainfall (Re) of the rain field have a positive correlation with the flow distance (L) of the debris flows. The signals recorded by the three-dimensional geophones showed that the frequency range of runoff events are between 20 and 90 Hz; the frequency range of debris flood events are between 30 and 80 Hz; the frequency range of earthquake events are below 5 Hz. The latter experiments of loose bed explores the granular flow pattern and failure processes, granular flow motion characteristics, accumulation parameters after runoff failures, and the correlations with stream power. The differences between the slope and the discharge conditions of the experimental tilting flume will cause different flow patterns. When the loose bed is fluidized by runoff, the ability of water flow to entrain the loose bed will be stronger as the slope and the discharge increase. The surge of the granular flow shows an increasing trend during the flow process. | en_US |